The Collaborative International Dictionary of English v.0.48:

Joyful \Joy"ful\, a.
   Full of joy; having or causing joy; very glad; as, a joyful
   heart. "Joyful tidings." --Shak.
   [1913 Webster]

         My soul shall be joyful in my God.       --Is. lxi. 10.
   [1913 Webster]

         Sad for their loss, but joyful of our life. --Pope.
   -- Joy"ful*ly, adv. -- Joy"ful*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

joyfully
    adv 1: in a joyous and gleeful manner; "the old man had greeted
           her gleefully" [syn: gleefully, joyously, joyfully]
           [ant: joylessly]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "joyfully":
   airily, blessedly, blissfully, blithely, cheerfully, cheerily,
   delightedly, ecstatically, elatedly, exultantly, genially, gladly,
   happily, hopefully, irrepressibly, jauntily, jubilantly, lightly,
   optimistically, pleasantly, rapturously, rhapsodically, smilingly,
   with good cheer, with pleasure